Millisecond Forums

How to measure latency of too slow responses

https://forums.millisecond.com/Topic9364.aspx

By Jennifer G - 12/17/2012

Hi everyone,



I'm currently programming my own version of the Flanker task and I'm having a question about how to record the response  latency for too slow responses.


Right now I'm having the response time out after 500 ms which should then terminate the trail. Responses that are made after these 500 ms are recorded as incorrect with a response latency of 500. Here is the code for one trial that does this:



<trial congruentleft>

/ pretrialpause= rand(800, 1000)

/ stimulustimes = [0=fixationcross;500=primeleft;1000=targetcongruentleft;1500=blank]

/responsetime = 1000

/ response = timeout(500)

/validresponse = ("1", "0")

/correctresponse = ("1")

</trial>



I'm wondering if it would be possible to keep everything as is in terms of how the trial appears on the screen, but also record the latency of responses that come in after 500ms have passed.


Any advice would be greatly appreciated!


Thanks!


 Jennifer
By Dave - 12/17/2012

If you want to record responses after 500 ms, you need to get rid of the response timeout.
By Jennifer G - 12/17/2012

Hi Dave,


Thanks for the quick response! As far as I understand, then Inquisit wouldn't know that any response slower than 500ms is incorrect. I'd like Inquisit to know that the response was too slow, but still have it record the latency of the response. I could easily just manually mark all responses slower than 500ms as too slow after data collection, but I'd also like to sometimes give participants feedback about total errors.


Jennifer
By Dave - 12/17/2012

Or you could use the <trial> element's /iscorrectresponse attribute to automatically score responses w/ latency > 500 as incorrect.